Blower.



D. E. MAXFIELD.

BLOWER.

APPLIUATION FILED SEPT. s, 190s.

1,128,475. Patented Feb.16, 1915.

3 SHEETS-SHEET 1.

ffyf Y 1 THE NORRIS PETERS C0.. PHOTU-LITHO. WASHlNGmN,

D. E. MAX'IELD.

BLOWER.

APPLICATION FILED SEPT. s, 1906.

Patented Feb. 16, 1915 3 SHEETS-SHEET 2.

1 l/rwg 0 THE NDRRIS PETERS C0.. PHUTO-LITHO., WASHINGION. D. C.V

D. E. MAXFIELD.

BLOWER.

APPLIGATION FILED SEPT. a, 1906. 1 Patented Feb.16, 1915. s SHBETSTSHBETs.

n if? n E THE NORRIS PETERS CO.. PHOTOLITHO., WASHINCroN. D

UNirnD srnrnsrn'rnn'r OFFICE.

DANIEL E. MAXFIELD, OF BOSTON, MASSACHUSETTS, ASSIG-NOR TO '.B. F.STURTEVANT COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OFMASSACHUSETTS.

BLOWER.

Specification of Letters Patent.

Patented Feb. 16, 1915.

Application led September 8, 1906. Serial No. 333,775.

To all whom it may concern: i

Be it known that I, DANIEL E.v MAXrIELD', a citizen of the UnitedStates, kresiding at Boston, in the county of Suffolk and State larlythat type of blower or exhauster em-y ploying peripherally dischargingvanes.

The invention consists 1n the blower herelinafter described andparticularly defined in the claims. p

In the accompanying drawings illustrating the preferred form of thelinvention Figure 1 is a side elevation, Fig. 2 is a sectional elevationof theblower or exhauster, Fig. 3 is a face view of a portion of thewheel, Fig. 4 is an end view enlarged of a portion of the periphery ofthewheel looking in the direction of the arrow m, Fig. 3, and Fig. 5 isa perspective view of'one of the vanes of the wheel. p

The casing 1 for the blower is, inthe illus# trated embodiment shown asmade of sheet metal having openings on both sides to permit ingressofiair to the interior or intake chamber of the wheel. A guide 3surrounds the opening and directs the entering air to the wheel 4. Theopening in the guide 3 is preferably large enough to permit the passageof the wheel therethrough. See Fig. 2. The wheel is mounted on a shaft 5supported in a bearing 6 at one end andat the other end connected to anengine, motor or other source of power.

The wheel 4, inthe machine of the drawings, comprises two portionsoperating to draw in the air from opposite sides. The wheel consists oftwo hub members 7 keyed to the shaft 5 and riveted to a central disk orplate 8 which forms the central support for the wheel. The periphery ofthewheel comprises two angle iron rings 9, vanes l0 peripheral braces 11and radial braces 12. The disk 8, angle iron rings 9 and the braces 11and 12 form the frame workor skeleton ofthe wheel upon which the vanes10 are mounted.y The angle iron rings 9 form the support for the outerends of vanes 10. The braces 11 consist of bolts extended through theinturned flange of the angle iron rings 9 and through the disk 8,distance pieces, conveniently consisting of pieces of pipe, surround thebolts and space the angle iron at the correct distance from the disk 8.The vanes 10 are secured at their inner ends to the disk 8 and at theirouter ends to the flanges of the angle iron rings 9. The vanes 10 act ascompression members and the braces 11 as tension members of a sort oftruss so that the stresses incident to the rotation of the wheel varedistributed through these members so as to avoid undue distortion. Thebraces 12 comprise means for centering the periphery of the fan withrelation to the shaft and for steadying it during rotation, and byreason of their angular p position they also act to prevent theperiphery of the wheel from moving or swaying longitudinally of theshaft. f

The vanes 10 are peculiar in construction. Each consists of a piece ofsheet metal, illustrated perhaps the best in Fig. 5, which islongitudinally stifi'ened by being curved in cross section. An ear 13 isformed at one end of the vane 10 by which it is riveted to the angleiron ring9. Ears 14 are formed at the other end of the vane by means ofwhich it is riveted to the disk 8. The vanes are secured to the outersurface of the angle iron rings 9 thereby occupying the position ofgreatest lineal velocity on the wheel so thaty they are located in themost eicient position. .The outer edges of the vanes are supported attheir inner ends by the rivets through the ears 14 near the outer edgeof the vane. At theouter end of the vane a radial corrugation 15 isformed which stiffens and supports the peripheral portion of the outerend of thevane.

In a fan in which the blades are arranged as elements of the cylindricalsurface determined thereby the fan delivers more air from the portion ofthe periphery the more `remote from the intake opening than it deliversat the portion of the periphery the nearer to the intake opening. Thisis believed to be because of the resistance `which the 'air offers tothe change in its direction of motionfrom an axial direction as itenters `the intake to a radial direction asL-jt passes through thewheel. Tests upon fans of such construction have revealed the fact thatthe difference between the delivery of the portion of the periphery ofthe fan remote from the intake opening and the delivery of the portionof the periphery of the fan adjacent to the intake opening is so greatthat in some cases the portion of the periphery adjacent to the intakeopenings actually drew in air from the outside. This objectionable modeof operation the applicant has endeavored to overcome and to a largeextent has overcome by arranging the vanes at an angle to the element ofthe surface which they determine. This angular arrangement of the vanesoperates to tend to equalize the pressure of delivery over the peripheryof the wheel and by virtue of the fact that the vanes tend to force theair passing out through them in the direction toward the rear end of theblade. that is. the portion of the blade striking the air last. This ismade clear by reference to Fig. 3. The air entering the end of the wheeltends to pass out through the portion of the wheel remote from theintake but the vanes, arranged at an angle as shown and moving in thedirec tion of the arrow 16, tend to counteract the effect of the inertiaof the incoming air and so to equalize the pressure of the air deliveredover the surface of the wheel. One important feature of the inventiontherefore resides in the angular disposition of the vanes with relationto an element of the surface which they determine so as to tend toequalize the peripheral pressure over the whole length of the wheel. Inthis connection it should be noted that each half of the wheel as shownin drawings, is a complete and independent blower irrespective of thepresence or absence of the other half and as a` consequence that theforegoing remarks relating to the variation of the pressure of the airdischarged by the wheel relate of course, only to one wheel. With adouble wheel the pressure of the air delivered would be the greatest inthe center in case the vanes were arranged as elements of the cylinderand least (or minus) at the ends. By the arrangement illustrated anddescribed the pressure is made more uniform.

Speaking with strict mathematical accuracy, the peripheral edges of thevanes (provided they are straight) determine, in the constructionillustrated in the drawings, a zone of a hyperboloid of revolution. Butthe zone used in the illustrated embodiment, is approximatelycylindrical in form and although the edges of the vanes should perhapsbe regarded as elements of the surface of a hyperboloid. speaking withsubstantial, and perhaps equal, correctness, they may be said todetermine a cylindrical surface and to be arran d in that surface at anangle to an cement thereof. The end of a vane the more remote from anintake openin is in advance (with relation to the directlon of rotationofthe wheel) of portions of the vane nearer the intake opening. Thevanes are arranged obliquely with relation to their direction of motionand their intake ends are behind their other ends. It will also beobserved that it is impossible to pass a lane through the axis of thewheel that wiliinot be angularly disposed to every vane of the wheel.All of these modes of describin the arrangement of the vanes may find teir brief equivalent in the statement that they have a skew arrangement.It is to be noted that whether the vanes are arranged to determine thesurface of a cylinder or other surface of revolution they always have askew arrangement.

The use of the word f blower herein is not intended to limit theinvention to use in av machine employed for blowing air as it is equallyuseful in machines for exhausting air. The medium operated upon by theblower has. for convenience. been re ferred to as air but it should beunderstood that other fluids or vapors are equally adapted to beoperated upon by the apparatus.

Where reference is made in the claims to the axial elements of a bladethis is to be understood as meaning the lines of intersection of theblade and concentric cylinders, the axis of which coincides with theaxis of the wheel.

Having thus described the invention, what is claimed is:

1. A blower having a wheel provided with peripherally discharging skewvanes having their intake ends behind with relation to their directionof motion. substantially as described.

2. A blower having a wheel provided with peripherally discharging vanes,a support to which the vanes are Secured, the vanes being provided witha supporting ear and with a radial corrugation extending into the ear tosti'en the vanes and to contribute to the support of their peripheraledges, substantially as described.

3. A blower having a wheel provided with an intake chamber within theperiphery thereof, and also provided with peripherally discharging skewvanes having their intake ends behind with relation to their directionof motion, substantially as described.

4. A blower, having a wheel provided with peripherally discharging vanesthe intake ends of which are open, a support to which the vanes aresecured, the vanes being provided with a supporting ear pro- ]eetingfrom the edge of the vane and with a corrugation extending into the ear,substantially as described.

5. A blower, having a wheel provided with peripherally discharging vanesthe intake ends of which are open, a support to which the vanes aresecured, the vanes being provided with a supporting ear projecting fromthe edge of the vane and adjacent the open end, substantially asdescribed.

6. `A blower having a wheel provided with two sets of peripherallydischarging skew vanes, ring supports for the outer ends of said vanes,means for supporting the inner ends of the vanes, the vanes in each sethaving their inner ends in advance of their outer ends with relation totheir direction of rotation, and a casing having intake openings on eachside of the wheel, substantially as described.

7. In a blower, the combination with a casing having an intake openingin its side, of a wheel rotatably mounted within the casing adjacentsaid opening and provided with peripherally discharging vanes, the endsof the vanes-distant from the intake opening being in advance of theends adjacent said opening with relation to the direction of rotation ofthe wheel, substantially as described. p

8. A centrifugal fan wheel of the multiblade drum type, comprisingblades, the axial elements of a portion of said blades being obliquewith reference to a plane passing through the aXis of rotation andintersecting the blade, with the ends remote blade drum type, comprisingblades having their outer edges arranged obliquely to the axis, saidedges at their ends remote from the intake being in advance of theirinlet ends.

10. A centrifugal fan Wheel of the multiblade drum type, comprisingblades curved in cross section with their concave sides leading, andwith their outer edges at the disk end in advance of said edges at theintake end.

11. A centrifugal fan wheel of the multiblade drum type comprisingblades, the axial elements of the greater portion of said blades beingoblique with reference to the plane passing through the axis of rotationand intersecting the blade, with the ends remote from the intake inadvance with respect to the direction of rotation, substantially asdescribed.

In testimony whereof I aiix my signature, in presence of two Witnesses.

DANIEL E. MAXFIELD.

Vitnesses:

HORACE VAN EVEREN, ALFRED I-I. HILDRETH.

`Copies of this patent may be obtained for five cents each, byaddressing the Commissioner of latente,

washington, n. c."

